We report on the processing and characterization of microstrip sensors and pad detectors produced on n- and p-type Magnetic Czochralski (MCz), Epitaxial (EPI) and Float Zone (FZ) silicon within the SMART project to develop radiation-hard silicon position sensitive detectors for future colliders. Each wafer contains 10 microstrip sensors with different geometries, several diodes and test structures. The isolation in the strip detectors produced on p-type material has been achieved by means of a uniform p-spray implantation, with doping of 3 x 10(12)cm(-2) (low-dose p-spray) and 5 x 10(12)cm(-2) (high-dose p-spray). The samples have undergone irradiations with 26MeV protons and reactor neutrons up to similar to 10(16)cm(-2) 1 MeV equivalent neutrons (n(eq)/cm(2)), and have been completely characterized before and after irradiation in terms of leakage current, depletion voltage and breakdown voltage. The current damage parameter alpha has been determined for all substrates. MCz diodes show less pronounced dependence of effective doping concentration N-eff on the fluence when compared to standard FZ silicon, giving results comparable to diffusion oxygenated FZ devices for all irradiation sources. The observed increase of Neff with fluence can be interpreted in EPI material as a net donor introduction process, overcompensating the usual acceptor introduction process. This effect is stronger for 26MeV proton irradiation than for neutron irradiation. (c) 2007 Elsevier B.V. All rights reserved.
Comparison of the radiation hardness of Magnetic Czochralski and Epitaxial silicon substrates after 26 MeV proton and reactor neutron irradiation
MESSINEO, ALBERTO MARIA;
2007-01-01
Abstract
We report on the processing and characterization of microstrip sensors and pad detectors produced on n- and p-type Magnetic Czochralski (MCz), Epitaxial (EPI) and Float Zone (FZ) silicon within the SMART project to develop radiation-hard silicon position sensitive detectors for future colliders. Each wafer contains 10 microstrip sensors with different geometries, several diodes and test structures. The isolation in the strip detectors produced on p-type material has been achieved by means of a uniform p-spray implantation, with doping of 3 x 10(12)cm(-2) (low-dose p-spray) and 5 x 10(12)cm(-2) (high-dose p-spray). The samples have undergone irradiations with 26MeV protons and reactor neutrons up to similar to 10(16)cm(-2) 1 MeV equivalent neutrons (n(eq)/cm(2)), and have been completely characterized before and after irradiation in terms of leakage current, depletion voltage and breakdown voltage. The current damage parameter alpha has been determined for all substrates. MCz diodes show less pronounced dependence of effective doping concentration N-eff on the fluence when compared to standard FZ silicon, giving results comparable to diffusion oxygenated FZ devices for all irradiation sources. The observed increase of Neff with fluence can be interpreted in EPI material as a net donor introduction process, overcompensating the usual acceptor introduction process. This effect is stronger for 26MeV proton irradiation than for neutron irradiation. (c) 2007 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
